Oceans Record Hottest June at 20.98C; El Niño to Drive Further Warming in 2026

The world's oceans experienced their hottest June on record, with global average sea surface temperatures reaching 20.98C. This surpasses previous records from 2023 and 2024, according to the European Union's Copernicus Marine Service. This record caps six months of near unprecedented ocean warmth in 2026, with average sea temperatures in the first half of the year at 20.04C, slightly below the 2024 high.

Scientists anticipate further temperature increases due to the onset of a potentially powerful El Niño weather pattern, which releases more heat into the atmosphere. Carlo Buontempo, director of Copernicus Climate Change Service, stated that current conditions could indicate a new phase leading to uncharted territory, with more records likely to fall. Simon Van Gennip, lead Oceanographer for the Copernicus Marine Service, expects 2026 to be among the warmest years ever recorded, attributing this to both El Niño and ongoing greenhouse gas emissions.

Oceans are crucial climate regulators, absorbing about 90% of excess heat from greenhouse gases. Warmer oceans contribute to sea level rise, fuel tropical cyclones, and create unbearable conditions for coral reefs, leading to bleaching and death. The first six months of 2026 saw widespread marine heatwaves affecting approximately 82% of the world's oceans, the second-largest extent after 2024. The Mediterranean broke its June record at 24.3C, and the tropical Pacific also had its hottest June ever at 27.26C.